Never, ever, ever, write your own userland threading library.

(rule broken by almost every language in common use, unfortunately)

That’s an absurd statement. Optimizing every language around what a runc-like program would need is absurd.

creata 2 hours ago | parent | prev [-]

Where does this advice come from? Most web servers would use a lot more resources if they didn't use userland threading, wouldn't they?

	▲	gertop an hour ago \| parent [-]
		I think you're confusing userland threading (also known as green threads) with a regular thread pool implementation (that uses regular OS threads). Because most web servers use OS threads. Nginx, Apache, litespeed, they all spin up `core count` threads but they can all work single threaded just fine as well.